A US woman who shot and killed her husband and two adult children before taking her own life is thought to have committed the shocking crime as a result of being ostracised from the religion she was raised in.

Every time I tell a mate I’m doing a story on cryptocurrency, they invariably ask me the same two questions: should they invest their own hard-earned money, and which cryptocurrency will get them a Lamborghini/yacht/island quickest?

Aust won't watch over Malaysia poll: Carr

The southeast Asian country's opposition leader Anwar Ibrahim has warned that "massive fraud" could prevent his coalition from winning at the polls and asked why Australia hasn't sent officials to monitor the election.

"It's quite baffling to my mind because the initial response from Australia is that there's no interference in domestic affairs," he told the ABC on Wednesday.

"We are not asking them to support any party.

"We are asking them to remain consistent with Australian foreign policy position in support of freedom and democracy."

Senator Carr on Thursday said Australia did not send election observers into foreign countries except on invitation from the government.

"We can't be a sort of court of disputed returns, or election authority, election commission, for another country," he told reporters in Sydney.